The nickel-catalyzed reaction of carbonyls and dienes was accomplished in a regio- and stereoselective fashion employing a stoichiometric amount of bis(pinacolato)diboron. In the presence of P(SiMe3)(3), this reductive coupling furnishes allyl boronic esters which are regioisomeric to those obtained with PCy3 as the ligand. The coupling product may be subject to oxidation, which furnishes the derived 1,3-diol, or allytation with an additional aldehyde, which furnishes the derived 1,6-diol in a stereoselective fashion.